Paper machine suction press



De- 7, 1954 L. HoRNBos-rEl.

PAPER MACHINE SUCTION PRESS Filed Jan. 11. 1950 United States Patent 'O 2,696,149 PAPER MAcHlNE sUcrIoN PRESS Lloyd Hornbostel, Beloit, Wis., assignor to Beloit Iron Works, Beloit, Wis., a corporation of Wisconsin The present invention relates to a paper machine suction press and more particularly to a reverse suction press for the removal of moisture from the wet paper web, including means for transferring the moist web from a first press felt to a second press felt without subjecting the web to the action of a press nip.

The present invention provides a novel form of reverse suction press for employment with a paper machine and is particularly adapted for employment in the manufacture of light-weight papers. Conventional reverse suction presses, as heretofore employed, are generally unsatisfactory for employment with light-weight webs, because of the necessity of reversing or otherwise drastically changing the direction of travel of the web during its passage through the reverse suction press, in which each side of the web is successively subjected to the action of a suction nip and to the action of a plain press roll. In addition, in conventional reverse presses, the transfer of the web from one press felt to another has been accomplished at a press nip, which is unsatisfactory due to the crushing of the lightweight web at the pressures necessarily present at the nip.

The present invention now provides a reverse suction press construction which obviates these disadvantages. Substantially straight forward travel of the web is provided with no doubling back of the web upon itself for subjection to the reverse suction nip. The only vertical travel of the web through the press of the present invention is utilized to complete the transfer of the web from the final press felt, and the absence of web reversals at high speed eliminates the possibility of the web being thrown from a felt or a guide roll. In addition, the present invention provides a reverse suction press having a vertical nip accommodating free drainage of moisture ahead of the nip and clean transfer by the utilization of gravitational forces acting upon the web beyond the nip to thereby strip the web from the reversed press felt. Further, the employment of a vertical nip permits the provision of a self-dumping doctor for the plain press roll of the reverse press with consequent operational advantages.

It is, therefore, an important object of the present invention to provide an improved paper machine suction press which eliminates the disadvantages of the prior art suction press constructions.

Another important object of the present invention is to provide an improved reverse suction press in which the web is transferred from a lirst press felt to a second press felt by means of suction developed at the reverse suction press, but without subjecting the web to nip pressure as it is transferred.

It is a further important object of the present invention to provide an improved paper machine suction press, including first and second reverse suction presses and means for conveying a moist web through the presses in a substantially straight forward travel and without drastic changes of web direction tending to throw the web from its carrying means.

Still another important object of the present invention is to provide an improved suction press for a paper making machine, including a reverse press having a vertical nip for receiving the web carried by a press felt lapped about the suction roll of the press, the vertical nip accommodating gravity drainage of moisture ahead of the press nip and also permitting the employment of gravitational forces in effecting the transfer of the web from the press felt.

Other and further important objects of this invention will be apparent from the disclosures in the specification and the accompanying drawings.

On the drawings:

Figure 1 is a schematic View of a paper machine section press section of the present invention; and

Figure 2 is a greatly enlarged fragmentary view of a section of the press of Figure l.

As shown on the drawings:

In Figure l, reference numeral 10 refers generally to a couch roll of conventional design having lapped thereabout a forming wire 11 of a paper 'tn'aking machine. A paper web 12 is formed on the forming wire 11 and is stripped therefrom and guided under a guide roll 13 onto a first press felt 14.

The press felt 14 is trained about a guide roll 15 to the nip of a first suction press' 16 consisting of an upper plain surfaced press roll 17 and a lower suction press roll 18. The suction press roll 18 is provided'with a rotatable, cylindrical, perforate shell 19 and an interior suction gland 20 having its suction area 21 underlying the nip of the press 16.

After the web 12 supported on the felt 14 has been passed through the nip of the press 16, the felt is passed about a shiftable guide roll 22 and then returned about a pair of closely spaced guide rolls 23 and a stretcher roll 24 to the initial guide roll 15.

The web 12 is removed from the felt 14 intermediate the press 16 and the guide roll 22 and is passed through the suction nip of a second or reverse suction press 25. The reverse press 25 comprises a pair of cooperating, generally horizontally arranged rolls cooperating to deizirie therebetween a vertically extending self-draining nip More particularly, the press 25 is defined by a plain press roll 27 and a suctionpress roll 28 more particularly illustrated in Figure 2. The suction press roll 28 includes a cylindrical, rotatable, perforate shell 30 and a suction gland 31 mounted therein. The suction gland 31 provides a pair of radially spaced suction areas 32 and 33 delined by spaced sealing strips 34 contacting the inner periphery of the shell. The suction area 33 is provided with a butterfly-type shut-off valve 35 provided with suitable controls and adapted to regulate the degree of suction within the area 33 to entirely shut off the suction in this area. The gland 31 is rotatably shiftable (i. e. mounted pivotally about the roll axis) within the shell 30 to a plurality of adjusted positions, including positions illustrated in solid and in dotted lines in Figure 2.

A second press felt 36 is lapped about a portion of vthe periphery of the suction press roll 28 to cover both the suction areas 32 and 33 thereof. yThis felt is trained about suitable guide rolls 37 and a stretcher roll 38 so as to pass about the suction areas of the roll 28 and to pass substantially vertically from the nip 26. It will be seen that suction exerted by the suction area 32 through the porous press felt 36 will serve to remove the web 12 from the felt 14 to the felt 36, with the felt 36 conveying the web about that portion of the periphery of the roll 28 lying between the suction areas 32 and 33 and across the suction area 33.

12 has passed through the nip 26 it plain press roll, 27 and will be trained thereabout over a guide roll 39 to desired further processing apparatus, as for example to a plain press 40. Any broke or paper stock adhering to the plain press roll 27 will be removed therefrom by a self-dumping or gravity assisted doctor 41, including a doctor blade 42 contacting the periphery of the roll 27.

The roll 22 is arcuately movable to lap the felt 14 and the web 12 carried thereby about a varying portion of the periphery of the suction press roll 28, this movement of the roll 22 being coordinated with the shifting of the suction gland 31 within the roll 28 to insure transfer of the web 12 to the roll 28. In this manner, it is possible to obtain the eliicient transfer of lightweight webs or other webs which are diicult to handle without the necessity of effecting the transfer at a pressure nip which might cause crushing of the web between the two felts.

After the web will adhere to the The advantages residing in the hereinbefore described invention will be appreciated by those skilled in the art and these advantages include, first, the transfer of the web from a first press felt to a second press felt by the use of suction alone and in the absence of a pressure nip which might cause crushing of the web'. Also, the adjustability of the guide roll 22 accommodates various types of webs with this adjustability being correlated with adjustment of the suction gland 31 to insure the transfer of the web.

The provision of the vertical nip 26 permits gravity drainage of moisture ahead of the nip so as to insure efiicient moisture removal from the web 12. Further, vertical travel of the web 12 through the nip 26 results in a vertical component which tends to hold the web 12 to the plain press roll 27. This clean transfer makes possible the employment of an unsupported web draw from the plain pressroll 27 to the press 40 without the possibility of tearing or otherwise damaging the web.

The valve 35 within the roll 28 is effective to cut off the suction area 33 during initial starting of the press section, so that suction is not lost as the leading relatively narrow tail of the web is threaded through the press. Of course, it is understood that when the gland 31 is moved to its dotted position in Figure 2, the felt 36 may be lapped further about the surface of the roll 28, so asv to completely cover the suction area 33 in its adjusted dotted position, thereby preventing substantial loss of the suction.

The adaptability of the assembly for use with a selfdumping doctor 41 is also an advantage of the present invention inasmuch as it permits the clean removal of broke or fibrous residue from the surface of the plain roll 27 without the broke falling upon a web, felt, roll, or like portion of the press assembly.

The entire construction hereinbefore set forth results in the passage of a moist web through a first suction press and a reverse suction press wtihout the necessity of doubling the web or otherwise drastically changing its position, with the exception of the passage of the web through the vertical nip 26. In this manner, the web is maintained substantially free of vertical components exerted thereon, and also drastic changes in the direction of web travel are prevented which would tend to throw the web olf its guide rolls or felts during travel through the press.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. A paper machine suction press comprising a first suction press roll, a first plain roll above said first suction roll and defining therewith a horizontal press nip, a first looped felt trained through said horizontal nip providing a downwardly inclined felt run at the outgoing side of said horizontal nip, a guide roll below the plane of said horizontal nip and within the loop of said first felt supporting the outgoing end of said downwardly inclined felt run, a shiftable mounting for vertical movement of said guide roll, a second suction press roll above said inclined felt run having a perforate rotatable shell and a suction gland disposed within the shell defining a first suction area at the bottom of the shell and a seciirst on the uprunning ond suction area circumferentially spaced from the side of the shell, a second felt lapped about said second suction roll and over both said areas, said guide roll`adjustably urging said inclined felt run upwardly against the first suction area of said second suction roll to eiect web transfer onto said second felt, a second plain roll cooperating with said second suction roll defining a vertical press nip adjacent said second suction area, and valve means on said gland controlling the suction at the second suction area, said suction gland being rotatably shiftable within the shell for movement of the first suction area relative to the downwardly inclined felt run and movement of the second suction area relative to said vertical press nip and the movement of said guide roll being coordinated with the shifting of said suction gland to eiect web transfer at said first suction area.

2. A paper machine suction press comprising a rst suction press roll, a first plain roll above said first suction roll and defining therewith a horizontal press nip,

' a first looped felt trained through said horizontal nip providing a downwardly inclined felt run at the outgoing side of said horizontal nip, a guide roll below the plane of said horizontal nip and within the loop of said first felt supporting the outgoing end of said downwardly inclined felt run, a shiftable mounting for vertical movement of said guide roll, a second suction press roll above said inclined felt run having a perforate rotatable shell and a suction gland disposed within the shell defining a first suction area at the bottom of the shell and a second suction area circumferentially spaced from the first on the uprunning side of the shell, a second felt lapped about said second suction roll and over both said areas, said guide roll adjustably urging said inclined felt run upwardly against the first suction area of said second suction roll to effect web transfer onto said second felt, a second plain roll cooperating with said sec ond suction roll defining a vertical press nip adjacent said second suction area, a self dumping doctor on the down running side of said second plain roll, and valve means on said gland controlling the suction at the second suction area, said suction gland being rotatably shiftable within the shell for movement of the rst suction area relative to the downwardly inclined felt run and movement of the second suction area relative to said vertical press nip and the movement of said guide roll being coordinated with the shifting of said suction gland to effect web transfer at said first suction area.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,959,520 Blais et al. May 22, 1934 2,111,834 Berry Mar. 22, 1938 2,186,171 Millspaugh Jan. 9, 1940 2,204,426 Millspaugh Iune 11, 1940 2,386,584 Berry Oct. 9, 1945 FOREIGN PATENTS Number Country Date 463,188 Great Britain Mar. 23, 1937 545,406 Great Britain May 22, 1942 

